Traditionally, a radio communication system such as the third generation mobile phone system executes process of accepting a call for allowing a communication origin (such as a fixed phone terminal) to call a communication destination (such as a mobile phone terminal) and of allocating a resource necessary for communication between the communication origin and the communication destination according to the type of the accepted call.
To execute the above-described process, a radio base station generally includes a call process controller configured to execute call process, and a baseband processor configured to allocate a resource corresponding to the type of a call, or namely, a baseband resource (hereinafter abbreviated as a BB resource as appropriate) which represents a processing capability necessary for carrying out encoding/decoding, spreading/despreading, and the like (Patent Document 1, for example).
Such a radio base station is capable of executing processing of a priority call (for example, an emergency call in case of a disaster or the like) which is to be handled in preference to a normal call, that is, to which a BB resource is allocated in preference to the normal call.
Specifically, the call process controller of the radio base station periodically acquires information indicating a used BB resource and judges whether or not to accept the normal call based on the acquired information. To be more precise, if the used BB resource exceeds a predetermined threshold, the call process controller judges not to accept the normal call in order to secure a BB resource allocatable to a priority call. Patent Document 1: Japanese Patent Application Publication No. 2006-86776 (Pages 3-4, FIG. 2)